Third-body perturbation in the case of elliptic orbits for the disturbing body

In the present work it is presented a semi-analytical and a numerical study of the perturbation caused in a spacecraft by a third body using a double averaged analytical model with the disturbing function expanded in Legendre polynomials up to the second-order. The important reason for this procedure is to eliminate the terms due to the short time periodic motion of the spacecraft and to show smooth curves for the evolution of the mean orbital elements for a long time period. The aim of this study is to calculate the effect of lunar perturbations on the orbits of spacecrafts that are traveling around the Earth. It is presented an analysis of the stability of a near-circular orbit and a study to know under which conditions this orbit remains near-circular. A study of the equatorial orbits is also performed.

Friction of sliding surfaces carrying adsorbed lubricant layers

In concentrated contacts the behaviour of lubricants is much modified by the high local pressures: changes can arise both from molecular ordering within the very thin film lubricant layers present at the interface as well as from the deposition on the component surfaces of more solid-like polymeric boundary layers. These 'third bodies' separating the solid surfaces may have rheological or mechanical properties very different from those observed in the bulk. Classical elasto-hydrodynamic theory considers the entrapped lubricant to exhibit a piezo-viscous behaviour while the conventional picture of more solid boundary lubricant layers views their shear strength r as being linearly dependent on local pressure p, so that T = TO + ap where TO and a are constants. If TO is relatively small, then the coefficient of friction \i = T Ip ~ a and so Amonton's laws are recovered. However, the properties of adsorbed or deposited surface films, or indeed other third bodies such as debris layers, may be more complex than this. A preliminary study has looked quantitatively at the influence of the pressure dependence of the shear strength of any surface layer on the overall friction coefficient of a contact which is made up of an array of asperities whose height varies in a Gaussian manner. Individual contact points may be elastic or plastic. The analysis results in plots of coefficient of friction versus the service or load parameter PIH&NRa where P is the nominal pressure on the contact, HS the hardness of the deforming surface, N the asperity density, R the mean radius of curvature of the asperities, and a is the standard deviation of their height distribution. In principle, any variation oft withp can be incorporated into the model; however, in this initial study we have used data on colloidal suspensions from the group at the Ecole Centrale de Lyon as well as examining the effect of functional relationships of somewhat greater complexity than a simple linear form. Results of the analysis indicate that variations in fj. are possible as the load is varied which depend on the statistical spread of behaviour at individual asperity contacts. The value of this analysis is that it attempts to combine the behaviour of films on the molecular scale with the topography of real engineering surfaces and so give an indication of the effects at the full-size or macro-scale that can be achieved by chemical or molecular surface engineering.

Characterizing wear processes on orthopaedic materials using scanning probe microscopy

The operational lifetime of hip replacement prostheses can be severely limited due to the occurrence of excessive wear at the load-bearing interfaces. The aim of this study was to investigate how the surface topography of articulating counterfaces evolves over the duration of a laboratory wear run. It was observed that modular stainless steel femoral heads wearing against ultrahigh molecular weight polyethylene (UHMWPE) can themselves be subject to wearing. A comparison with retrieved in vivo-aged femoral heads shows many topographical similarities: in a qualitative sense, scratching and pitting are evident on laboratory and in vivo-worn femoral heads; quantitatively, roughness comparisons between the new and worn devices are seen to increase typically by a factor of 4 after laboratory wearing. The observations suggest that a particular wear mode, namely third-body wear, is responsible for the increased roughness. It is conjectured that third bodies might arise through surface fatigue wear on the metal counterface, Wear debris is also observed to have been generated from the polymer surface, creating rounded debris with sizes predominantly in the range 0.4-0.8 microns: dimensions that are comparable to values previously reported for in vivo generated debris.

Re-thinking home economics : from modern to postmodern accounts of pedagogical bodies

Two perceptions of the marginality of home economics are widespread across educational and other contexts. One is that home economics and those who engage in its pedagogy are inevitably marginalised within patriarchal relations in education and culture. This is because home economics is characterised as women's knowledge, for the private domain of the home. The other perception is that only orthodox epistemological frameworks of inquiry should be used to interrogate this state of affairs. These perceptions have prompted leading theorists in the field to call for non-essentialist approaches to research in order to re-think the thinking that has produced this cul-de-sac positioning of home economics as a body of knowledge and a site of teacher practice. This thesis takes up the challenge of working to locate a space outside the frame of modernist research theory and methods, recognising that this shift in epistemology is necessary to unsettle the idea that home economics is inevitably marginalised. The purpose of the study is to reconfigure how we have come to think about home economics teachers and the profession of home economics as a site of cultural practice, in order to think it otherwise (Lather, 1991). This is done by exploring how the culture of home economics is being contested from within. To do so, the thesis uses a 'posthumanist' approach, which rejects the conception of the individual as a unitary and fixed entity, but instead as a subject in process, shaped by desires and language which are not necessarily consciously determined. This posthumanist project focuses attention on pedagogical body subjects as the 'unsaid' of home economics research. It works to transcend the modernist dualism of mind/body, and other binaries central to modernist work, including private/public, male/female,paid/unpaid, and valued/unvalued. In so doing, it refuses the simple margin/centre geometry so characteristic of current perceptions of home economics itself. Three studies make up this work. Studies one and two serve to document the disciplined body of home economics knowledge, the governance of which works towards normalisation of the 'proper' home economics teacher. The analysis of these accounts of home economics teachers by home economics teachers, reveals that home economics teachers are 'skilled' yet they 'suffer' for their profession. Further,home economics knowledge is seen to be complicit in reinforcing the traditional roles of masculinity and femininity, thereby reinforcing heterosexual normativity which is central to patriarchal society. The third study looks to four 'atypical'subjects who defy the category of 'proper' and 'normal' home economics teacher. These 'atypical' bodies are 'skilled' but fiercely reject the label of 'suffering'. The discussion of the studies is a feminist poststructural account, using Russo's (1994) notion of the grotesque body, which is emergent from Bakhtin's (1968) theory of the carnivalesque. It draws on the 'shreds' of home economics pedagogy,scrutinising them for their subversive, transformative potential. In this analysis, the giving and taking of pleasure and fun in the home economics classroom presents moments of surprise and of carnival. Foucault's notion of the construction of the ethical individual shows these 'atypical' bodies to be 'immoderate' yet striving hard to be 'continent' body subjects. This research captures moments of transgression which suggest that transformative moments are already embodied in the pedagogical practices of home economics teachers, and these can be 'seen' when re-looking through postmodemist lenses. Hence, the cultural practices ofhome economics as inevitably marginalised are being contested from within. Until now, home economics as a lived culture has failed to recognise possibilities for reconstructing its own field beyond the confines of modernity. This research is an example of how to think about home economics teachers and the profession as a reconfigured cultural practice. Future research about home economics as a body of knowledge and a site of teacher practice need not retell a simple story of oppression. Using postmodemist epistemologies is one way to provide opportunities for new ways of looking.

α-Synuclein pathology in very elderly Finns : A population-based clinico-neuropathologic and molecular genetic study of Dementia with Lewy bodies

Populations in developed countries are ageing fast. The elderly have the greatest incidence of de-mentia, and thus the increase in the number of demented individuals, increases the immediate costs for the governments concerning healthcare and hospital treatment. Attention is being paid to disorders behind cognitive impairment with behavioural and psychological symptoms, which are enormous contributors to the hospital care required for the elderly. The highest dreams are in prevention; however, before discovering the tools for preventing dementia, the pathogenesis behind dementia disorders needs to be understood. Dementia with Lewy bodies (DLB), a relatively recently discovered dementia disorder compared to Alzheimer’s disease (AD), is estimated to account for up to one third of primary degenerative dementia, thus being the second most common cause of dementia in the elderly. Nevertheless, the impact of neuropathological and genetic findings on the clinical syndrome of DLB is not fully established. In this present series of studies, the frequency of neuropathological findings of DLB and its relation to the clinical findings was evaluated in a cohort of subjects with primary degenerative dementia and in a population-based prospective cohort study of individuals aged 85 years or older. α-synuclein (αS) immunoreactive pathology classifiable according to the DLB consensus criteria was found in one fourth of the primary degenerative dementia subjects. In the population-based study, the corresponding figure was one third of the population, 38% of the demented and one fifth of the non-demented very elderly Finns. However, in spite of the frequent discovery of αS pathology, its association with the clinical symptoms was quite poor. Indeed, the common clinical features of DLB, hypokinesia and visual hallucinations, associated better with the severe neurofibrillary AD-type pathology than with the extensive (diffuse neocortical) αS pathology when both types of pathology were taken into account. The severity of the neurofibrillary AD-type pathology (Braak stage) associated with the extent of αS pathology in the brain. In addition, the genetic study showed an interaction between tau and αS; common variation in the αS gene (SNCA) associated significantly with the severity of the neurofibrillary AD-type pathology and nominally significantly with the extensive αS pathology. Further, the relevance and temporal course of the substantia nigra (SN) degeneration and of the spinal cord αS pathology were studied in relation to αS pathology in the brain. The linear association between the extent of αS pathology in the brain and the neuron loss in SN suggests that in DLB the degeneration of SN proceeds as the αS pathology extends from SN to the neocortex instead of early destruction of SN seen in Parkinson’s disease (PD). Furthermore, the extent of αS pathology in the brain associated with the severity of αS pathology in the thoracic and sacral autonomic nuclei of the spinal cord. The thoracic αS pathology was more common and more severe compared to sacral cord, suggesting that the progress of αS pathology proceeds downwards from the brainstem towards the sacral spinal cord.

Precipitation-induced runoff and leaching from milled peat mining mires by peat types : a comparative method for estimating the loading of water bodies during peat pruduction

Precipitation-induced runoff and leaching from milled peat mining mires by peat types: a comparative method for estimating the loading of water bodies during peat production. This research project in environmental geology has arisen out of an observed need to be able to predict more accurately the loading of watercourses with detrimental organic substances and nutrients from already existing and planned peat production areas, since the authorities capacity for insisting on such predictions covering the whole duration of peat production in connection with evaluations of environmental impact is at present highly limited. National and international decisions regarding monitoring of the condition of watercourses and their improvement and restoration require more sophisticated evaluation methods in order to be able to forecast watercourse loading and its environmental impacts at the stage of land-use planning and preparations for peat production.The present project thus set out from the premise that it would be possible on the basis of existing mire and peat data properties to construct estimates for the typical loading from production mires over the whole duration of their exploitation. Finland has some 10 million hectares of peatland, accounting for almost a third of its total area. Macroclimatic conditions have varied in the course of the Holocene growth and development of this peatland, and with them the habitats of the peat-forming plants. Temperatures and moisture conditions have played a significant role in determining the dominant species of mire plants growing there at any particular time, the resulting mire types and the accumulation and deposition of plant remains to form the peat. The above climatic, environmental and mire development factors, together with ditching, have contributed, and continue to contribute, to the existence of peat horizons that differ in their physical and chemical properties, leading to differences in material transport between peatlands in a natural state and mires that have been ditched or prepared for forestry and peat production. Watercourse loading from the ditching of mires or their use for peat production can have detrimental effects on river and lake environments and their recreational use, especially where oxygen-consuming organic solids and soluble organic substances and nutrients are concerned. It has not previously been possible, however, to estimate in advance the watercourse loading likely to arise from ditching and peat production on the basis of the characteristics of the peat in a mire, although earlier observations have indicated that watercourse loading from peat production can vary greatly and it has been suggested that differences in peat properties may be of significance in this. Sprinkling is used here in combination with simulations of conditions in a milled peat production area to determine the influence of the physical and chemical properties of milled peats in production mires on surface runoff into the drainage ditches and the concentrations of material in the runoff water. Sprinkling and extraction experiments were carried out on 25 samples of milled Carex (C) and Sphagnum (S) peat of humification grades H 2.5 8.5 with moisture content in the range 23.4 89% on commencement of the first sprinkling, which was followed by a second sprinkling 24 hours later. The water retention capacity of the peat was best, and surface runoff lowest, with Sphagnum and Carex peat samples of humification grades H 2.5 6 in the moisture content class 56 75%. On account of the hydrophobicity of dry peat, runoff increased in a fairly regular manner with drying of the sample from 55% to 24 30%. Runoff from the samples with an original moisture content over 55% increased by 63% in the second round of sprinkling relative to the first, as they had practically reached saturation point on the first occasion, while those with an original moisture content below 55% retained their high runoff in the second round, due to continued hydrophobicity. The well-humified samples (H 6.5 8.5) with a moisture content over 80% showed a low water retention capacity and high runoff in both rounds of sprinkling. Loading of the runoff water with suspended solids, total phosphorus and total nitrogen, and also the chemical oxygen demand (CODMn O2), varied greatly in the sprinkling experiment, depending on the peat type and degree of humification, but concentrations of the same substances in the two sprinklings were closely or moderately closely correlated and these correlations were significant. The concentrations of suspended solids in the runoff water observed in the simulations of a peat production area and the direct surface runoff from it into the drainage ditch system in response to rain (sprinkling intensity 1.27 mm/min) varied c. 60-fold between the degrees of humification in the case of the Carex peats and c. 150-fold for the Sphagnum peats, while chemical oxygen demand varied c. 30-fold and c. 50-fold, respectively, total phosphorus c. 60-fold and c. 66-fold, total nitrogen c. 65-fold and c. 195-fold and ammonium nitrogen c. 90-fold and c. 30-fold. The increases in concentrations in the runoff water were very closely correlated with increases in humification of the peat. The correlations of the concentrations measured in extraction experiments (48 h) with peat type and degree of humification corresponded to those observed in the sprinkler experiments. The resulting figures for the surface runoff from a peat production area into the drainage ditches simulated by means of sprinkling and material concentrations in the runoff water were combined with statistics on the mean extent of daily rainfall (0 67 mm) during the frost-free period of the year (May October) over an observation period of 30 years to yield typical annual loading figures (kg/ha) for suspended solids (SS), chemical oxygen demand of organic matter (CODmn O2), total phosphorus (tot. P) and total nitrogen (tot. N) entering the ditches with respect to milled Carex (C) and Sphagnum (S) peats of humification grades H 2.5 8.5. In order to calculate the loading of drainage ditches from a milled peat production mire with the aid of these annual comparative values (in kg/ha), information is required on the properties of the intended production mire and its peat. Once data are available on the area of the mire, its peat depth, peat types and their degrees of humification, dry matter content, calorific value and corresponding energy content, it is possible to produce mutually comparable estimates for individual mires with respect to the annual loading of the drainage ditch system and the surrounding watercourse for the whole service life of the production area, the duration of this service life, determinations of energy content and the amount of loading per unit of energy generated (kg/MWh). In the 8 mires in the Köyhäjoki basin, Central Ostrobothnia, taken as an example, the loading of suspended solids (SS) in the drainage ditch networks calculated on the basis of the typical values obtained here and existing mire and peat data and expressed per unit of energy generated varied between the mires and horizons in the range 0.9 16.5 kg/MWh. One of the aims of this work was to develop means of making better use of existing mire and peat data and the results of corings and other field investigations. In this respect combination of the typical loading values (kg/ha) obtained here for S, SC, CS and C peats and the various degrees of humification (H 2.5 8.5) with the above mire and peat data by means of a computer program for the acquisition and handling of such data would enable all the information currently available and that deposited in the system in the future to be used for defining watercourse loading estimates for mires and comparing them with the corresponding estimates of energy content. The intention behind this work has been to respond to the challenge facing the energy generation industry to find larger peat production areas that exert less loading on the environment and to that facing the environmental authorities to improve the means available for estimating watercourse loading from peat production and its environmental impacts in advance. The results conform well to the initial hypothesis and to the goals laid down for the research and should enable watercourse loading from existing and planned peat production to be evaluated better in the future and the resulting impacts to be taken into account when planning land use and energy generation. The advance loading information available in this way would be of value in the selection of individual peat production areas, the planning of their exploitation, the introduction of water protection measures and the planning of loading inspections, in order to achieve controlled peat production that pays due attention to environmental considerations.

Serving Multiple Masters: Exploring HRD in the Context of Third Sector Partnerships for Public Service Delivery

Organisations in the Non-Profit and Voluntary (NPV) sector increasingly face challenging and uncertain times with an increasing shift from public grant funding towards contract funding. As a result many of these changes employees in such organisations have often found themselves working more closely under contract with colleagues in public sector organisations in order to provide public services. Using a multiple case study methodology and in-depth interviewing of a range of stakeholders form two large Northern Irish based Non Profit Organisations in the social care sector, the purpose of this research was to
investigate HRD and people management issues and how a turbulent environment can affect how organisations approach HRD strategy and implementation.

The research identifies the importance placed upon NPOs adopting HRD strategies and addressing the development of unique and specialised skills in order to claw back power within the relationships they serve with statutory funding bodies. However this research also notes that the manner in which HRD and its associated issues are considered within NPOs can have an impact on the loyalty and commitment of the workforce which serves them. What is of concern is that the context for the delivery of public services under contract is putting increasing strain on NPOs and this has been felt markedly by their respective workforces, and unless strong values-led leadership and managerial practice is in
place in NPOs, the voluntary-centred ethos of those who work in the sector may be significantly damaged.

Acoustic radiation and scattering from cylindrical bodies and analysis of transducer arrays

New mathematical methods to analytically investigate linear acoustic radiation and scattering from cylindrical bodies and transducer arrays are presented. Three problems of interest involving cylinders in an infinite fluid are studied. In all the three problems, the Helmholtz equation is used to model propagation through the fluid and the beam patterns of arrays of transducers are studied. In the first problem, a method is presented to determine the omni-directional and directional far-field pressures radiated by a cylindrical transducer array in an infinite rigid cylindrical baffle. The solution to the Helmholtz equation and the displacement continuity condition at the interface between the array and the surrounding water are used to determine the pressure. The displacement of the surface of each transducer is in the direction of the normal to the array and is assumed to be uniform. Expressions are derived for the pressure radiated by a sector of the array vibrating in-phase, the entire array vibrating in-phase, and a sector of the array phase-shaded to simulate radiation from a rectangular piston. It is shown that the uniform displacement required for generating a source level of 220 dB ref. μPa @ 1m that is omni directional in the azimuthal plane is in the order of 1 micron for typical arrays. Numerical results are presented to show that there is only a small difference between the on-axis pressures radiated by phased cylindrical arrays and planar arrays. The problem is of interest because cylindrical arrays of projectors are often used to search for underwater objects. In the second problem, the errors, when using data-independent, classical, energy and split beam correlation methods, in finding the direction of arrival (DOA) of a plane acoustic wave, caused by the presence of a solid circular elastic cylindrical stiffener near a linear array of hydrophones, are investigated. Scattering from the effectively infinite cylinder is modeled using the exact axisymmetric equations of motion and the total pressures at the hydrophone locations are computed. The effect of the radius of the cylinder, a, the distance between the cylinder and the array, b, the number of hydrophones in the array, 2H, and the angle of incidence of the wave, α, on the error in finding the DOA are illustrated using numerical results. For an array that is about 30 times the wavelength and for small angles of incidence (α<10), the error in finding the DOA using the energy method is less than that using the split beam correlation method with beam steered to α; and in some cases, the error increases when b increases; and the errors in finding the DOA using the energy method and the split beam correlation method with beam steered to α vary approximately as a7 / 4 . The problem is of interest because elastic stiffeners – in nearly acoustically transparent sonar domes that are used to protect arrays of transducers – scatter waves that are incident on it and cause an error in the estimated direction of arrival of the wave. In the third problem, a high-frequency ray-acoustics method is presented and used to determine the interior pressure field when a plane wave is normally incident on a fluid cylinder embedded in another infinite fluid. The pressure field is determined by using geometrical and physical acoustics. The interior pressure is expressed as the sum of the pressures due to all rays that pass through a point. Numerical results are presented for ka = 20 to 100 where k is the acoustic wavenumber of the exterior fluid and a is the radius of the cylinder. The results are in good agreement with those obtained using field theory. The directional responses, to the plane wave, of sectors of a circular array of uniformly distributed hydrophones in the embedded cylinder are then computed. The sectors are used to simulate linear arrays with uniformly distributed normals by using delays. The directional responses are compared with the output from an array in an infinite homogenous fluid. These outputs are of interest as they are used to determine the direction of arrival of the plane wave. Numerical results are presented for a circular array with 32 hydrophones and 12 hydrophones in each sector. The problem is of interest because arrays of hydrophones are housed inside sonar domes and acoustic plane waves from distant sources are scattered by the dome filled with fresh water and cause deterioration in the performance of the array.

Planet formation in a triple stellar system: implications of the third star's orbital inclination

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The Formation and Circulation of Early Yanzi Lore, Fourth Century B.C. - Third Century A.D.

Thesis (Ph.D.)--University of Washington, 2016-06

Reforming public services in the UK:Bringing in the third sector

In the UK, the government continues its project to reform public services. Earlier projects have focused on the modernization of public sector organizations; in the latest round of reform, New Labour has focused on widening choice and the personalization of services. To this end, the government has been working with Third Sector (TS) organizations to expand their role in shaping, commissioning and delivering public services. The government's vision is predicated on a normative assertion, that, unlike traditional public sector organizations, TS bodies create public value by being more innovative, are inspired by altruistic aims and values, and have greater commitment to their clients. This paper reviews recent policy and questions whether the government's policy is flawed, contradictory and risks damaging the attributes of the TS admired by New Labour. © 2007 The Author. Journal compilation © 2007 Blackwell Publishing Ltd.

Babies, bodies and entitlement: gendered aspects of access to citizenship in the Republic of Ireland

Since the mid-1990s, automatic citizenship for children born in the Republic has been a source of growing debate against a backdrop of increasing immigration and the peace process. In June 2004, the debate culminated in a referendum, opening the way to a constitutional amendment that attaches residence qualifications to the hitherto unfettered entitlement to citizenship available through ius soli. Arguments for the amendment were couched in terms of a threat posed by Third World women having babies in Ireland to obtain residence, and a putative obligation to the EU to harmonise citizenship laws. This article explores how pregnant foreign women’s bodies became a site of perplexity about the borders of the twenty-first century Irish nation. It is therefore suggested that neither the ‘racial state’ theories nor feminist theories of the nation-state account fully for this. On closer inspection, the seemingly sui generis case of the Irish referendum is therefore fruitful in that it demands further reflection in terms of bridging gaps in the existing theory.

Laminar distribution of amyloid-beta (Abeta) deposits in dementia with Lewy bodies: comparison with Alzheimer's disease

Significant amyloid-beta (Abeta) deposition in cases of dementia with Lewy bodies (DLB) may represent concurrent Alzheimer's disease (AD). To test this hypothesis, the laminar distribution of the diffuse, primitive, and classic Abeta deposits was studied in the frontal and temporal cortex in cases of DLB and were compared with AD. In DLB, the diffuse and primitive deposits exhibited two common patterns of distribution; either maximum density occurred in the upper cortical laminae or a bimodal distribution was present with density peaks in the upper and lower laminae. In addition, a bimodal distribution of the classic deposits was observed in approximately half of the cortical areas analysed. A number of differences in the laminar distributions of Abeta deposits were observed in DLB and AD. First, the proportion of the primitive relative to the diffuse and classic deposits present was lower in DLB compared with AD. Second, the primitive deposits were more frequently bimodally distributed in DLB. Third, the density of the diffuse deposits reached a maximum lower in the cortical profile in AD. These data suggest differences in the pattern of cortical degeneration in the two disorders and therefore, DLB cases with significant Abeta pathology may not represent the coexistence of DLB and AD.

Differences in the prevalence of ankylosing spondylitis in primary and secondary care : only one-third of patients are managed in rheumatology

Funding: No specific funding was received from any bodies in the public, commercial or not-for-profit sectors to carry out the work described in this article. Disclosure statement: G.T.J. and G.J.M. have received research funding from Pfizer and AbbVie. L.E.D. conducted the analysis while funded by an Medical Research Council PhD studentship